Information about quality of care is of increasing interest to consumers, purchasers, and providers of health care. In response, federal and state agencies, provider organizations, and private coalitions are generating hospital outcome studies. Yet fundamental questions about these studies have never been answered. Do consumers use information about hospital outcomes in choosing physicians and hospitals, if it is available? Do purchasers use such information in creating provider networks? Do providers use such information in the quality improvement process? If so, do outcomes change as a result? What is the relationship between external and internal review of quality, and how can organizations become receptive to external review? In short, what are the outcomes of hospital outcome studies? The specific aims of the proposed research include: (1) to evaluate the impact of publicly released hospital outcomes data on AMIs, diskectomies, and deliveries in CA, and data on CABGs and PTCAs in NY, on hospital volumes and referral patterns; (2) to evaluate whether this impact varies by age, gender, race/ethnicity, insurance source, diagnostic category, urgency of admission, or market characteristics; (3) to evaluate the impact of publicly released outcomes data on hospital-specific outcomes, coding of clinical risk factors, patient case mix, and statewide outcomes; (4) to explore how hospitals in CA and NY have used outcomes data, and to solicit feedback concerning the optimal content and format of outcomes reports; (5) to explore how other interest groups, such as consumer organizations and purchasers, have used outcomes data, and to solicit similar feedback; and (6) to apply these results in designing a new generation of hospital outcome studies that will be more responsive to the needs of consumers, providers, and purchasers. The first five questions will be reevaluated in the final year of the research program. The analyses of consumer behavior will use California's Patient Discharge Data Set and New York's Statewide Planning and Research Cooperative System, Cardiac Surgery Reporting System, and Coronary Angioplasty Reporting System. All admissions to non-federal, non-HMO, acute care hospitals among adults with conditions other than mental disorders, injury, poisoning, and rehabilitation between 1/1/94 and 12/31/95 will be examined. Total and condition-specific hospital volumes and volumes of longdistance patients will be compared before and after publication of outcomes data, both overall and stratified as above. The quantitative analyses of provider behavior will use the same data systems, but will be limited to patients eligible for inclusion in the relevant outcomes study. Risk-adjusted outcome rates will be compared before and after publication of outcomes data. Any observed improvement at hospitals with high outcome rates will be attributed proportionately to changes in coding practice, selective out-referral, or improved quality of care. At the same time, mail and telephone surveys will be conducted to explore how providers and purchasers have assimilated and responded to risk-adjusted outcomes data. The results of this research will be used to improve the usefulness of outcomes reports in CA and NY; the impact of these reports will be comprehensively reevaluated after some of the recommended changes have been implemented.